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1 ------------------------------------------------------------------------------
2 -- --
3 -- GNAT COMPILER COMPONENTS --
4 -- --
5 -- P A R . C H 9 --
6 -- --
7 -- B o d y --
8 -- --
9 -- Copyright (C) 1992-2005, Free Software Foundation, Inc. --
10 -- --
11 -- GNAT is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNAT; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, USA. --
21 -- --
22 -- GNAT was originally developed by the GNAT team at New York University. --
23 -- Extensive contributions were provided by Ada Core Technologies Inc. --
24 -- --
25 ------------------------------------------------------------------------------
27 pragma Style_Checks (All_Checks);
28 -- Turn off subprogram body ordering check. Subprograms are in order by RM
29 -- section rather than alphabetical.
31 separate (Par)
32 package body Ch9 is
34 -- Local subprograms, used only in this chapter
36 function P_Accept_Alternative return Node_Id;
37 function P_Delay_Alternative return Node_Id;
38 function P_Delay_Relative_Statement return Node_Id;
39 function P_Delay_Until_Statement return Node_Id;
40 function P_Entry_Barrier return Node_Id;
41 function P_Entry_Body_Formal_Part return Node_Id;
42 function P_Entry_Declaration return Node_Id;
43 function P_Entry_Index_Specification return Node_Id;
44 function P_Protected_Definition return Node_Id;
45 function P_Protected_Operation_Declaration_Opt return Node_Id;
46 function P_Protected_Operation_Items return List_Id;
47 function P_Task_Definition return Node_Id;
48 function P_Task_Items return List_Id;
50 -----------------------------
51 -- 9.1 Task (also 10.1.3) --
52 -----------------------------
54 -- TASK_TYPE_DECLARATION ::=
55 -- task type DEFINING_IDENTIFIER [KNOWN_DISCRIMINANT_PART]
56 -- [is [new INTERFACE_LIST with] TASK_DEFINITION];
58 -- SINGLE_TASK_DECLARATION ::=
59 -- task DEFINING_IDENTIFIER
60 -- [is [new INTERFACE_LIST with] TASK_DEFINITION];
62 -- TASK_BODY ::=
63 -- task body DEFINING_IDENTIFIER is
64 -- DECLARATIVE_PART
65 -- begin
66 -- HANDLED_SEQUENCE_OF_STATEMENTS
67 -- end [task_IDENTIFIER]
69 -- TASK_BODY_STUB ::=
70 -- task body DEFINING_IDENTIFIER is separate;
72 -- This routine scans out a task declaration, task body, or task stub
74 -- The caller has checked that the initial token is TASK and scanned
75 -- past it, so that Token is set to the token after TASK
77 -- Error recovery: cannot raise Error_Resync
79 function P_Task return Node_Id is
80 Name_Node : Node_Id;
81 Task_Node : Node_Id;
82 Task_Sloc : Source_Ptr;
84 begin
85 Push_Scope_Stack;
86 Scope.Table (Scope.Last).Etyp := E_Name;
87 Scope.Table (Scope.Last).Ecol := Start_Column;
88 Scope.Table (Scope.Last).Sloc := Token_Ptr;
89 Scope.Table (Scope.Last).Lreq := False;
90 Task_Sloc := Prev_Token_Ptr;
92 if Token = Tok_Body then
93 Scan; -- past BODY
94 Name_Node := P_Defining_Identifier (C_Is);
95 Scope.Table (Scope.Last).Labl := Name_Node;
97 if Token = Tok_Left_Paren then
98 Error_Msg_SC ("discriminant part not allowed in task body");
99 Discard_Junk_List (P_Known_Discriminant_Part_Opt);
100 end if;
102 TF_Is;
104 -- Task stub
106 if Token = Tok_Separate then
107 Scan; -- past SEPARATE
108 Task_Node := New_Node (N_Task_Body_Stub, Task_Sloc);
109 Set_Defining_Identifier (Task_Node, Name_Node);
110 TF_Semicolon;
111 Pop_Scope_Stack; -- remove unused entry
113 -- Task body
115 else
116 Task_Node := New_Node (N_Task_Body, Task_Sloc);
117 Set_Defining_Identifier (Task_Node, Name_Node);
118 Parse_Decls_Begin_End (Task_Node);
119 end if;
121 return Task_Node;
123 -- Otherwise we must have a task declaration
125 else
126 if Token = Tok_Type then
127 Scan; -- past TYPE
128 Task_Node := New_Node (N_Task_Type_Declaration, Task_Sloc);
129 Name_Node := P_Defining_Identifier;
130 Set_Defining_Identifier (Task_Node, Name_Node);
131 Scope.Table (Scope.Last).Labl := Name_Node;
132 Set_Discriminant_Specifications
133 (Task_Node, P_Known_Discriminant_Part_Opt);
135 else
136 Task_Node := New_Node (N_Single_Task_Declaration, Task_Sloc);
137 Name_Node := P_Defining_Identifier (C_Is);
138 Set_Defining_Identifier (Task_Node, Name_Node);
139 Scope.Table (Scope.Last).Labl := Name_Node;
141 if Token = Tok_Left_Paren then
142 Error_Msg_SC ("discriminant part not allowed for single task");
143 Discard_Junk_List (P_Known_Discriminant_Part_Opt);
144 end if;
145 end if;
147 -- Parse optional task definition. Note that P_Task_Definition scans
148 -- out the semicolon as well as the task definition itself.
150 if Token = Tok_Semicolon then
152 -- A little check, if the next token after semicolon is
153 -- Entry, then surely the semicolon should really be IS
155 Scan; -- past semicolon
157 if Token = Tok_Entry then
158 Error_Msg_SP (""";"" should be IS");
159 Set_Task_Definition (Task_Node, P_Task_Definition);
160 else
161 Pop_Scope_Stack; -- Remove unused entry
162 end if;
163 else
164 TF_Is; -- must have IS if no semicolon
166 -- Ada 2005 (AI-345)
168 if Token = Tok_New then
169 Scan; -- past NEW
171 if Ada_Version < Ada_05 then
172 Error_Msg_SP ("task interface is an Ada 2005 extension");
173 Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
174 end if;
176 Set_Interface_List (Task_Node, New_List);
178 loop
179 Append (P_Qualified_Simple_Name, Interface_List (Task_Node));
180 exit when Token /= Tok_And;
181 Scan; -- past AND
182 end loop;
184 if Token /= Tok_With then
185 Error_Msg_SC ("WITH expected");
186 end if;
188 Scan; -- past WITH
190 if Token = Tok_Private then
191 Error_Msg_SP
192 ("PRIVATE not allowed in task type declaration");
193 end if;
194 end if;
196 Set_Task_Definition (Task_Node, P_Task_Definition);
197 end if;
199 return Task_Node;
200 end if;
201 end P_Task;
203 --------------------------------
204 -- 9.1 Task Type Declaration --
205 --------------------------------
207 -- Parsed by P_Task (9.1)
209 ----------------------------------
210 -- 9.1 Single Task Declaration --
211 ----------------------------------
213 -- Parsed by P_Task (9.1)
215 --------------------------
216 -- 9.1 Task Definition --
217 --------------------------
219 -- TASK_DEFINITION ::=
220 -- {TASK_ITEM}
221 -- [private
222 -- {TASK_ITEM}]
223 -- end [task_IDENTIFIER];
225 -- The caller has already made the scope stack entry
227 -- Note: there is a small deviation from official syntax here in that we
228 -- regard the semicolon after end as part of the Task_Definition, and in
229 -- the official syntax, it's part of the enclosing declaration. The reason
230 -- for this deviation is that otherwise the end processing would have to
231 -- be special cased, which would be a nuisance!
233 -- Error recovery: cannot raise Error_Resync
235 function P_Task_Definition return Node_Id is
236 Def_Node : Node_Id;
238 begin
239 Def_Node := New_Node (N_Task_Definition, Token_Ptr);
240 Set_Visible_Declarations (Def_Node, P_Task_Items);
242 if Token = Tok_Private then
243 Scan; -- past PRIVATE
244 Set_Private_Declarations (Def_Node, P_Task_Items);
246 -- Deal gracefully with multiple PRIVATE parts
248 while Token = Tok_Private loop
249 Error_Msg_SC ("only one private part allowed per task");
250 Scan; -- past PRIVATE
251 Append_List (P_Task_Items, Private_Declarations (Def_Node));
252 end loop;
253 end if;
255 End_Statements (Def_Node);
256 return Def_Node;
257 end P_Task_Definition;
259 --------------------
260 -- 9.1 Task Item --
261 --------------------
263 -- TASK_ITEM ::= ENTRY_DECLARATION | REPRESENTATION_CLAUSE
265 -- This subprogram scans a (possibly empty) list of task items and pragmas
267 -- Error recovery: cannot raise Error_Resync
269 -- Note: a pragma can also be returned in this position
271 function P_Task_Items return List_Id is
272 Items : List_Id;
273 Item_Node : Node_Id;
274 Decl_Sloc : Source_Ptr;
276 begin
277 -- Get rid of active SIS entry from outer scope. This means we will
278 -- miss some nested cases, but it doesn't seem worth the effort. See
279 -- discussion in Par for further details
281 SIS_Entry_Active := False;
283 -- Loop to scan out task items
285 Items := New_List;
287 Decl_Loop : loop
288 Decl_Sloc := Token_Ptr;
290 if Token = Tok_Pragma then
291 Append (P_Pragma, Items);
293 -- Ada 2005 (AI-397): Reserved words NOT and OVERRIDING
294 -- may begin an entry declaration.
296 elsif Token = Tok_Entry
297 or else Token = Tok_Not
298 or else Token = Tok_Overriding
299 then
300 Append (P_Entry_Declaration, Items);
302 elsif Token = Tok_For then
303 -- Representation clause in task declaration. The only rep
304 -- clause which is legal in a protected is an address clause,
305 -- so that is what we try to scan out.
307 Item_Node := P_Representation_Clause;
309 if Nkind (Item_Node) = N_At_Clause then
310 Append (Item_Node, Items);
312 elsif Nkind (Item_Node) = N_Attribute_Definition_Clause
313 and then Chars (Item_Node) = Name_Address
314 then
315 Append (Item_Node, Items);
317 else
318 Error_Msg
319 ("the only representation clause " &
320 "allowed here is an address clause!", Decl_Sloc);
321 end if;
323 elsif Token = Tok_Identifier
324 or else Token in Token_Class_Declk
325 then
326 Error_Msg_SC ("illegal declaration in task definition");
327 Resync_Past_Semicolon;
329 else
330 exit Decl_Loop;
331 end if;
332 end loop Decl_Loop;
334 return Items;
335 end P_Task_Items;
337 --------------------
338 -- 9.1 Task Body --
339 --------------------
341 -- Parsed by P_Task (9.1)
343 ----------------------------------
344 -- 9.4 Protected (also 10.1.3) --
345 ----------------------------------
347 -- PROTECTED_TYPE_DECLARATION ::=
348 -- protected type DEFINING_IDENTIFIER [KNOWN_DISCRIMINANT_PART]
349 -- is [new INTERFACE_LIST with] PROTECTED_DEFINITION;
351 -- SINGLE_PROTECTED_DECLARATION ::=
352 -- protected DEFINING_IDENTIFIER
353 -- is [new INTERFACE_LIST with] PROTECTED_DEFINITION;
355 -- PROTECTED_BODY ::=
356 -- protected body DEFINING_IDENTIFIER is
357 -- {PROTECTED_OPERATION_ITEM}
358 -- end [protected_IDENTIFIER];
360 -- PROTECTED_BODY_STUB ::=
361 -- protected body DEFINING_IDENTIFIER is separate;
363 -- This routine scans out a protected declaration, protected body
364 -- or a protected stub.
366 -- The caller has checked that the initial token is PROTECTED and
367 -- scanned past it, so Token is set to the following token.
369 -- Error recovery: cannot raise Error_Resync
371 function P_Protected return Node_Id is
372 Name_Node : Node_Id;
373 Protected_Node : Node_Id;
374 Protected_Sloc : Source_Ptr;
376 begin
377 Push_Scope_Stack;
378 Scope.Table (Scope.Last).Etyp := E_Name;
379 Scope.Table (Scope.Last).Ecol := Start_Column;
380 Scope.Table (Scope.Last).Lreq := False;
381 Protected_Sloc := Prev_Token_Ptr;
383 if Token = Tok_Body then
384 Scan; -- past BODY
385 Name_Node := P_Defining_Identifier (C_Is);
386 Scope.Table (Scope.Last).Labl := Name_Node;
388 if Token = Tok_Left_Paren then
389 Error_Msg_SC ("discriminant part not allowed in protected body");
390 Discard_Junk_List (P_Known_Discriminant_Part_Opt);
391 end if;
393 TF_Is;
395 -- Protected stub
397 if Token = Tok_Separate then
398 Scan; -- past SEPARATE
399 Protected_Node := New_Node (N_Protected_Body_Stub, Protected_Sloc);
400 Set_Defining_Identifier (Protected_Node, Name_Node);
401 TF_Semicolon;
402 Pop_Scope_Stack; -- remove unused entry
404 -- Protected body
406 else
407 Protected_Node := New_Node (N_Protected_Body, Protected_Sloc);
408 Set_Defining_Identifier (Protected_Node, Name_Node);
409 Set_Declarations (Protected_Node, P_Protected_Operation_Items);
410 End_Statements (Protected_Node);
411 end if;
413 return Protected_Node;
415 -- Otherwise we must have a protected declaration
417 else
418 if Token = Tok_Type then
419 Scan; -- past TYPE
420 Protected_Node :=
421 New_Node (N_Protected_Type_Declaration, Protected_Sloc);
422 Name_Node := P_Defining_Identifier (C_Is);
423 Set_Defining_Identifier (Protected_Node, Name_Node);
424 Scope.Table (Scope.Last).Labl := Name_Node;
425 Set_Discriminant_Specifications
426 (Protected_Node, P_Known_Discriminant_Part_Opt);
428 else
429 Protected_Node :=
430 New_Node (N_Single_Protected_Declaration, Protected_Sloc);
431 Name_Node := P_Defining_Identifier (C_Is);
432 Set_Defining_Identifier (Protected_Node, Name_Node);
434 if Token = Tok_Left_Paren then
435 Error_Msg_SC
436 ("discriminant part not allowed for single protected");
437 Discard_Junk_List (P_Known_Discriminant_Part_Opt);
438 end if;
440 Scope.Table (Scope.Last).Labl := Name_Node;
441 end if;
443 T_Is;
445 -- Ada 2005 (AI-345)
447 if Token = Tok_New then
448 Scan; -- past NEW
450 if Ada_Version < Ada_05 then
451 Error_Msg_SP ("task interface is an Ada 2005 extension");
452 Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
453 end if;
455 Set_Interface_List (Protected_Node, New_List);
457 loop
458 Append (P_Qualified_Simple_Name,
459 Interface_List (Protected_Node));
461 exit when Token /= Tok_And;
462 Scan; -- past AND
463 end loop;
465 if Token /= Tok_With then
466 Error_Msg_SC ("WITH expected");
467 end if;
469 Scan; -- past WITH
471 if Token = Tok_Private then
472 Error_Msg_SP
473 ("PRIVATE not allowed in protected type declaration");
474 end if;
475 end if;
477 Set_Protected_Definition (Protected_Node, P_Protected_Definition);
478 return Protected_Node;
479 end if;
480 end P_Protected;
482 -------------------------------------
483 -- 9.4 Protected Type Declaration --
484 -------------------------------------
486 -- Parsed by P_Protected (9.4)
488 ---------------------------------------
489 -- 9.4 Single Protected Declaration --
490 ---------------------------------------
492 -- Parsed by P_Protected (9.4)
494 -------------------------------
495 -- 9.4 Protected Definition --
496 -------------------------------
498 -- PROTECTED_DEFINITION ::=
499 -- {PROTECTED_OPERATION_DECLARATION}
500 -- [private
501 -- {PROTECTED_ELEMENT_DECLARATION}]
502 -- end [protected_IDENTIFIER]
504 -- PROTECTED_ELEMENT_DECLARATION ::=
505 -- PROTECTED_OPERATION_DECLARATION
506 -- | COMPONENT_DECLARATION
508 -- The caller has already established the scope stack entry
510 -- Error recovery: cannot raise Error_Resync
512 function P_Protected_Definition return Node_Id is
513 Def_Node : Node_Id;
514 Item_Node : Node_Id;
516 begin
517 Def_Node := New_Node (N_Protected_Definition, Token_Ptr);
519 -- Get rid of active SIS entry from outer scope. This means we will
520 -- miss some nested cases, but it doesn't seem worth the effort. See
521 -- discussion in Par for further details
523 SIS_Entry_Active := False;
525 -- Loop to scan visible declarations (protected operation declarations)
527 Set_Visible_Declarations (Def_Node, New_List);
529 loop
530 Item_Node := P_Protected_Operation_Declaration_Opt;
531 exit when No (Item_Node);
532 Append (Item_Node, Visible_Declarations (Def_Node));
533 end loop;
535 -- Deal with PRIVATE part (including graceful handling
536 -- of multiple PRIVATE parts).
538 Private_Loop : while Token = Tok_Private loop
539 if No (Private_Declarations (Def_Node)) then
540 Set_Private_Declarations (Def_Node, New_List);
541 else
542 Error_Msg_SC ("duplicate private part");
543 end if;
545 Scan; -- past PRIVATE
547 Declaration_Loop : loop
548 if Token = Tok_Identifier then
549 P_Component_Items (Private_Declarations (Def_Node));
550 else
551 Item_Node := P_Protected_Operation_Declaration_Opt;
552 exit Declaration_Loop when No (Item_Node);
553 Append (Item_Node, Private_Declarations (Def_Node));
554 end if;
555 end loop Declaration_Loop;
556 end loop Private_Loop;
558 End_Statements (Def_Node);
559 return Def_Node;
560 end P_Protected_Definition;
562 ------------------------------------------
563 -- 9.4 Protected Operation Declaration --
564 ------------------------------------------
566 -- PROTECTED_OPERATION_DECLARATION ::=
567 -- SUBPROGRAM_DECLARATION
568 -- | ENTRY_DECLARATION
569 -- | REPRESENTATION_CLAUSE
571 -- Error recovery: cannot raise Error_Resync
573 -- Note: a pragma can also be returned in this position
575 -- We are not currently permitting representation clauses to appear as
576 -- protected operation declarations, do we have to rethink this???
578 function P_Protected_Operation_Declaration_Opt return Node_Id is
579 L : List_Id;
580 P : Source_Ptr;
582 function P_Entry_Or_Subprogram_With_Indicator return Node_Id;
583 -- Ada 2005 (AI-397): Parse an entry or a subprogram with an overriding
584 -- indicator. The caller has checked that the initial token is NOT or
585 -- OVERRIDING.
587 ------------------------------------------
588 -- P_Entry_Or_Subprogram_With_Indicator --
589 ------------------------------------------
591 function P_Entry_Or_Subprogram_With_Indicator return Node_Id is
592 Decl : Node_Id := Error;
593 Is_Overriding : Boolean := False;
594 Not_Overriding : Boolean := False;
596 begin
597 if Token = Tok_Not then
598 Scan; -- past NOT
600 if Token = Tok_Overriding then
601 Scan; -- past OVERRIDING
602 Not_Overriding := True;
603 else
604 Error_Msg_SC ("OVERRIDING expected!");
605 end if;
607 else
608 Scan; -- past OVERRIDING
609 Is_Overriding := True;
610 end if;
612 if (Is_Overriding or else Not_Overriding) then
613 if Ada_Version < Ada_05 then
614 Error_Msg_SP (" overriding indicator is an Ada 2005 extension");
615 Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
617 elsif Token = Tok_Entry then
618 Decl := P_Entry_Declaration;
620 Set_Must_Override (Decl, Is_Overriding);
621 Set_Must_Not_Override (Decl, Not_Overriding);
623 elsif Token = Tok_Function or else Token = Tok_Procedure then
624 Decl := P_Subprogram (Pf_Decl);
626 Set_Must_Override (Specification (Decl), Is_Overriding);
627 Set_Must_Not_Override (Specification (Decl), Not_Overriding);
629 else
630 Error_Msg_SC ("ENTRY, FUNCTION or PROCEDURE expected!");
631 end if;
632 end if;
634 return Decl;
635 end P_Entry_Or_Subprogram_With_Indicator;
637 -- Start of processing for P_Protected_Operation_Declaration_Opt
639 begin
640 -- This loop runs more than once only when a junk declaration
641 -- is skipped.
643 loop
644 if Token = Tok_Pragma then
645 return P_Pragma;
647 elsif Token = Tok_Not or else Token = Tok_Overriding then
648 return P_Entry_Or_Subprogram_With_Indicator;
650 elsif Token = Tok_Entry then
651 return P_Entry_Declaration;
653 elsif Token = Tok_Function or else Token = Tok_Procedure then
654 return P_Subprogram (Pf_Decl);
656 elsif Token = Tok_Identifier then
657 L := New_List;
658 P := Token_Ptr;
659 Skip_Declaration (L);
661 if Nkind (First (L)) = N_Object_Declaration then
662 Error_Msg
663 ("component must be declared in private part of " &
664 "protected type", P);
665 else
666 Error_Msg
667 ("illegal declaration in protected definition", P);
668 end if;
670 elsif Token in Token_Class_Declk then
671 Error_Msg_SC ("illegal declaration in protected definition");
672 Resync_Past_Semicolon;
674 -- Return now to avoid cascaded messages if next declaration
675 -- is a valid component declaration.
677 return Error;
679 elsif Token = Tok_For then
680 Error_Msg_SC
681 ("representation clause not allowed in protected definition");
682 Resync_Past_Semicolon;
684 else
685 return Empty;
686 end if;
687 end loop;
688 end P_Protected_Operation_Declaration_Opt;
690 -----------------------------------
691 -- 9.4 Protected Operation Item --
692 -----------------------------------
694 -- PROTECTED_OPERATION_ITEM ::=
695 -- SUBPROGRAM_DECLARATION
696 -- | SUBPROGRAM_BODY
697 -- | ENTRY_BODY
698 -- | REPRESENTATION_CLAUSE
700 -- This procedure parses and returns a list of protected operation items
702 -- We are not currently permitting representation clauses to appear
703 -- as protected operation items, do we have to rethink this???
705 function P_Protected_Operation_Items return List_Id is
706 Item_List : List_Id;
708 begin
709 Item_List := New_List;
711 loop
712 if Token = Tok_Entry or else Bad_Spelling_Of (Tok_Entry) then
713 Append (P_Entry_Body, Item_List);
715 elsif Token = Tok_Function or else Bad_Spelling_Of (Tok_Function)
716 or else
717 Token = Tok_Procedure or else Bad_Spelling_Of (Tok_Procedure)
718 then
719 Append (P_Subprogram (Pf_Decl_Pbod), Item_List);
721 elsif Token = Tok_Pragma or else Bad_Spelling_Of (Tok_Pragma) then
722 P_Pragmas_Opt (Item_List);
724 elsif Token = Tok_Private or else Bad_Spelling_Of (Tok_Private) then
725 Error_Msg_SC ("PRIVATE not allowed in protected body");
726 Scan; -- past PRIVATE
728 elsif Token = Tok_Identifier then
729 Error_Msg_SC
730 ("all components must be declared in spec!");
731 Resync_Past_Semicolon;
733 elsif Token in Token_Class_Declk then
734 Error_Msg_SC ("this declaration not allowed in protected body");
735 Resync_Past_Semicolon;
737 else
738 exit;
739 end if;
740 end loop;
742 return Item_List;
743 end P_Protected_Operation_Items;
745 ------------------------------
746 -- 9.5.2 Entry Declaration --
747 ------------------------------
749 -- ENTRY_DECLARATION ::=
750 -- [OVERRIDING_INDICATOR]
751 -- entry DEFINING_IDENTIFIER [(DISCRETE_SUBTYPE_DEFINITION)]
752 -- PARAMETER_PROFILE;
754 -- The caller has checked that the initial token is ENTRY, NOT or
755 -- OVERRIDING.
757 -- Error recovery: cannot raise Error_Resync
759 function P_Entry_Declaration return Node_Id is
760 Decl_Node : Node_Id;
761 Scan_State : Saved_Scan_State;
763 -- Flags for optional overriding indication. Two flags are needed,
764 -- to distinguish positive and negative overriding indicators from
765 -- the absence of any indicator.
767 Is_Overriding : Boolean := False;
768 Not_Overriding : Boolean := False;
770 begin
771 -- Ada 2005 (AI-397): Scan leading overriding indicator
773 if Token = Tok_Not then
774 Scan; -- past NOT
776 if Token = Tok_Overriding then
777 Scan; -- part OVERRIDING
778 Not_Overriding := True;
779 else
780 Error_Msg_SC ("OVERRIDING expected!");
781 end if;
783 elsif Token = Tok_Overriding then
784 Scan; -- part OVERRIDING
785 Is_Overriding := True;
786 end if;
788 if (Is_Overriding or else Not_Overriding) then
789 if Ada_Version < Ada_05 then
790 Error_Msg_SP (" overriding indicator is an Ada 2005 extension");
791 Error_Msg_SP ("\unit must be compiled with -gnat05 switch");
793 elsif Token /= Tok_Entry then
794 Error_Msg_SC ("ENTRY expected!");
795 end if;
796 end if;
798 Decl_Node := New_Node (N_Entry_Declaration, Token_Ptr);
799 Scan; -- past ENTRY
801 Set_Defining_Identifier
802 (Decl_Node, P_Defining_Identifier (C_Left_Paren_Semicolon));
804 -- If left paren, could be (Discrete_Subtype_Definition) or Formal_Part
806 if Token = Tok_Left_Paren then
807 Scan; -- past (
809 -- If identifier after left paren, could still be either
811 if Token = Tok_Identifier then
812 Save_Scan_State (Scan_State); -- at Id
813 Scan; -- past Id
815 -- If comma or colon after Id, must be Formal_Part
817 if Token = Tok_Comma or else Token = Tok_Colon then
818 Restore_Scan_State (Scan_State); -- to Id
819 Set_Parameter_Specifications (Decl_Node, P_Formal_Part);
821 -- Else if Id wi no comma or colon, must be discrete subtype defn
823 else
824 Restore_Scan_State (Scan_State); -- to Id
825 Set_Discrete_Subtype_Definition
826 (Decl_Node, P_Discrete_Subtype_Definition);
827 T_Right_Paren;
828 Set_Parameter_Specifications (Decl_Node, P_Parameter_Profile);
829 end if;
831 -- If no Id, must be discrete subtype definition
833 else
834 Set_Discrete_Subtype_Definition
835 (Decl_Node, P_Discrete_Subtype_Definition);
836 T_Right_Paren;
837 Set_Parameter_Specifications (Decl_Node, P_Parameter_Profile);
838 end if;
839 end if;
841 if Is_Overriding then
842 Set_Must_Override (Decl_Node);
843 elsif Not_Overriding then
844 Set_Must_Not_Override (Decl_Node);
845 end if;
847 -- Error recovery check for illegal return
849 if Token = Tok_Return then
850 Error_Msg_SC ("entry cannot have return value!");
851 Scan;
852 Discard_Junk_Node (P_Subtype_Indication);
853 end if;
855 -- Error recovery check for improper use of entry barrier in spec
857 if Token = Tok_When then
858 Error_Msg_SC ("barrier not allowed here (belongs in body)");
859 Scan; -- past WHEN;
860 Discard_Junk_Node (P_Expression_No_Right_Paren);
861 end if;
863 TF_Semicolon;
864 return Decl_Node;
866 exception
867 when Error_Resync =>
868 Resync_Past_Semicolon;
869 return Error;
870 end P_Entry_Declaration;
872 -----------------------------
873 -- 9.5.2 Accept Statement --
874 -----------------------------
876 -- ACCEPT_STATEMENT ::=
877 -- accept entry_DIRECT_NAME
878 -- [(ENTRY_INDEX)] PARAMETER_PROFILE [do
879 -- HANDLED_SEQUENCE_OF_STATEMENTS
880 -- end [entry_IDENTIFIER]];
882 -- The caller has checked that the initial token is ACCEPT
884 -- Error recovery: cannot raise Error_Resync. If an error occurs, the
885 -- scan is resynchronized past the next semicolon and control returns.
887 function P_Accept_Statement return Node_Id is
888 Scan_State : Saved_Scan_State;
889 Accept_Node : Node_Id;
890 Hand_Seq : Node_Id;
892 begin
893 Push_Scope_Stack;
894 Scope.Table (Scope.Last).Sloc := Token_Ptr;
895 Scope.Table (Scope.Last).Ecol := Start_Column;
897 Accept_Node := New_Node (N_Accept_Statement, Token_Ptr);
898 Scan; -- past ACCEPT
899 Scope.Table (Scope.Last).Labl := Token_Node;
901 Set_Entry_Direct_Name (Accept_Node, P_Identifier (C_Do));
903 -- Left paren could be (Entry_Index) or Formal_Part, determine which
905 if Token = Tok_Left_Paren then
906 Save_Scan_State (Scan_State); -- at left paren
907 Scan; -- past left paren
909 -- If first token after left paren not identifier, then Entry_Index
911 if Token /= Tok_Identifier then
912 Set_Entry_Index (Accept_Node, P_Expression);
913 T_Right_Paren;
914 Set_Parameter_Specifications (Accept_Node, P_Parameter_Profile);
916 -- First token after left paren is identifier, could be either case
918 else -- Token = Tok_Identifier
919 Scan; -- past identifier
921 -- If identifier followed by comma or colon, must be Formal_Part
923 if Token = Tok_Comma or else Token = Tok_Colon then
924 Restore_Scan_State (Scan_State); -- to left paren
925 Set_Parameter_Specifications (Accept_Node, P_Parameter_Profile);
927 -- If identifier not followed by comma/colon, must be entry index
929 else
930 Restore_Scan_State (Scan_State); -- to left paren
931 Scan; -- past left paren (again!)
932 Set_Entry_Index (Accept_Node, P_Expression);
933 T_Right_Paren;
934 Set_Parameter_Specifications (Accept_Node, P_Parameter_Profile);
935 end if;
936 end if;
937 end if;
939 -- Scan out DO if present
941 if Token = Tok_Do then
942 Scope.Table (Scope.Last).Etyp := E_Name;
943 Scope.Table (Scope.Last).Lreq := False;
944 Scan; -- past DO
945 Hand_Seq := P_Handled_Sequence_Of_Statements;
946 Set_Handled_Statement_Sequence (Accept_Node, Hand_Seq);
947 End_Statements (Handled_Statement_Sequence (Accept_Node));
949 -- Exception handlers not allowed in Ada 95 node
951 if Present (Exception_Handlers (Hand_Seq)) then
952 if Ada_Version = Ada_83 then
953 Error_Msg_N
954 ("(Ada 83) exception handlers in accept not allowed",
955 First_Non_Pragma (Exception_Handlers (Hand_Seq)));
956 end if;
957 end if;
959 else
960 Pop_Scope_Stack; -- discard unused entry
961 TF_Semicolon;
962 end if;
964 return Accept_Node;
966 -- If error, resynchronize past semicolon
968 exception
969 when Error_Resync =>
970 Resync_Past_Semicolon;
971 Pop_Scope_Stack; -- discard unused entry
972 return Error;
974 end P_Accept_Statement;
976 ------------------------
977 -- 9.5.2 Entry Index --
978 ------------------------
980 -- Parsed by P_Expression (4.4)
982 -----------------------
983 -- 9.5.2 Entry Body --
984 -----------------------
986 -- ENTRY_BODY ::=
987 -- entry DEFINING_IDENTIFIER ENTRY_BODY_FORMAL_PART ENTRY_BARRIER is
988 -- DECLARATIVE_PART
989 -- begin
990 -- HANDLED_SEQUENCE_OF_STATEMENTS
991 -- end [entry_IDENTIFIER];
993 -- The caller has checked that the initial token is ENTRY
995 -- Error_Recovery: cannot raise Error_Resync
997 function P_Entry_Body return Node_Id is
998 Entry_Node : Node_Id;
999 Formal_Part_Node : Node_Id;
1000 Name_Node : Node_Id;
1002 begin
1003 Push_Scope_Stack;
1004 Entry_Node := New_Node (N_Entry_Body, Token_Ptr);
1005 Scan; -- past ENTRY
1007 Scope.Table (Scope.Last).Ecol := Start_Column;
1008 Scope.Table (Scope.Last).Lreq := False;
1009 Scope.Table (Scope.Last).Etyp := E_Name;
1011 Name_Node := P_Defining_Identifier;
1012 Set_Defining_Identifier (Entry_Node, Name_Node);
1013 Scope.Table (Scope.Last).Labl := Name_Node;
1015 Formal_Part_Node := P_Entry_Body_Formal_Part;
1016 Set_Entry_Body_Formal_Part (Entry_Node, Formal_Part_Node);
1018 Set_Condition (Formal_Part_Node, P_Entry_Barrier);
1019 Parse_Decls_Begin_End (Entry_Node);
1020 return Entry_Node;
1021 end P_Entry_Body;
1023 -----------------------------------
1024 -- 9.5.2 Entry Body Formal Part --
1025 -----------------------------------
1027 -- ENTRY_BODY_FORMAL_PART ::=
1028 -- [(ENTRY_INDEX_SPECIFICATION)] [PARAMETER_PART]
1030 -- Error_Recovery: cannot raise Error_Resync
1032 function P_Entry_Body_Formal_Part return Node_Id is
1033 Fpart_Node : Node_Id;
1034 Scan_State : Saved_Scan_State;
1036 begin
1037 Fpart_Node := New_Node (N_Entry_Body_Formal_Part, Token_Ptr);
1039 -- See if entry index specification present, and if so parse it
1041 if Token = Tok_Left_Paren then
1042 Save_Scan_State (Scan_State); -- at left paren
1043 Scan; -- past left paren
1045 if Token = Tok_For then
1046 Set_Entry_Index_Specification
1047 (Fpart_Node, P_Entry_Index_Specification);
1048 T_Right_Paren;
1049 else
1050 Restore_Scan_State (Scan_State); -- to left paren
1051 end if;
1053 -- Check for (common?) case of left paren omitted before FOR. This
1054 -- is a tricky case, because the corresponding missing left paren
1055 -- can cause real havoc if a formal part is present which gets
1056 -- treated as part of the discrete subtype definition of the
1057 -- entry index specification, so just give error and resynchronize
1059 elsif Token = Tok_For then
1060 T_Left_Paren; -- to give error message
1061 Resync_To_When;
1062 end if;
1064 Set_Parameter_Specifications (Fpart_Node, P_Parameter_Profile);
1065 return Fpart_Node;
1066 end P_Entry_Body_Formal_Part;
1068 --------------------------
1069 -- 9.5.2 Entry Barrier --
1070 --------------------------
1072 -- ENTRY_BARRIER ::= when CONDITION
1074 -- Error_Recovery: cannot raise Error_Resync
1076 function P_Entry_Barrier return Node_Id is
1077 Bnode : Node_Id;
1079 begin
1080 if Token = Tok_When then
1081 Scan; -- past WHEN;
1082 Bnode := P_Expression_No_Right_Paren;
1084 if Token = Tok_Colon_Equal then
1085 Error_Msg_SC (""":="" should be ""=""");
1086 Scan;
1087 Bnode := P_Expression_No_Right_Paren;
1088 end if;
1090 else
1091 T_When; -- to give error message
1092 Bnode := Error;
1093 end if;
1095 TF_Is;
1096 return Bnode;
1097 end P_Entry_Barrier;
1099 --------------------------------------
1100 -- 9.5.2 Entry Index Specification --
1101 --------------------------------------
1103 -- ENTRY_INDEX_SPECIFICATION ::=
1104 -- for DEFINING_IDENTIFIER in DISCRETE_SUBTYPE_DEFINITION
1106 -- Error recovery: can raise Error_Resync
1108 function P_Entry_Index_Specification return Node_Id is
1109 Iterator_Node : Node_Id;
1111 begin
1112 Iterator_Node := New_Node (N_Entry_Index_Specification, Token_Ptr);
1113 T_For; -- past FOR
1114 Set_Defining_Identifier (Iterator_Node, P_Defining_Identifier (C_In));
1115 T_In;
1116 Set_Discrete_Subtype_Definition
1117 (Iterator_Node, P_Discrete_Subtype_Definition);
1118 return Iterator_Node;
1119 end P_Entry_Index_Specification;
1121 ---------------------------------
1122 -- 9.5.3 Entry Call Statement --
1123 ---------------------------------
1125 -- Parsed by P_Name (4.1). Within a select, an entry call is parsed
1126 -- by P_Select_Statement (9.7)
1128 ------------------------------
1129 -- 9.5.4 Requeue Statement --
1130 ------------------------------
1132 -- REQUEUE_STATEMENT ::= requeue entry_NAME [with abort];
1134 -- The caller has checked that the initial token is requeue
1136 -- Error recovery: can raise Error_Resync
1138 function P_Requeue_Statement return Node_Id is
1139 Requeue_Node : Node_Id;
1141 begin
1142 Requeue_Node := New_Node (N_Requeue_Statement, Token_Ptr);
1143 Scan; -- past REQUEUE
1144 Set_Name (Requeue_Node, P_Name);
1146 if Token = Tok_With then
1147 Scan; -- past WITH
1148 T_Abort;
1149 Set_Abort_Present (Requeue_Node, True);
1150 end if;
1152 TF_Semicolon;
1153 return Requeue_Node;
1154 end P_Requeue_Statement;
1156 --------------------------
1157 -- 9.6 Delay Statement --
1158 --------------------------
1160 -- DELAY_STATEMENT ::=
1161 -- DELAY_UNTIL_STATEMENT
1162 -- | DELAY_RELATIVE_STATEMENT
1164 -- The caller has checked that the initial token is DELAY
1166 -- Error recovery: cannot raise Error_Resync
1168 function P_Delay_Statement return Node_Id is
1169 begin
1170 Scan; -- past DELAY
1172 -- The following check for delay until misused in Ada 83 doesn't catch
1173 -- all cases, but it's good enough to catch most of them!
1175 if Token_Name = Name_Until then
1176 Check_95_Keyword (Tok_Until, Tok_Left_Paren);
1177 Check_95_Keyword (Tok_Until, Tok_Identifier);
1178 end if;
1180 if Token = Tok_Until then
1181 return P_Delay_Until_Statement;
1182 else
1183 return P_Delay_Relative_Statement;
1184 end if;
1185 end P_Delay_Statement;
1187 --------------------------------
1188 -- 9.6 Delay Until Statement --
1189 --------------------------------
1191 -- DELAY_UNTIL_STATEMENT ::= delay until delay_EXPRESSION;
1193 -- The caller has checked that the initial token is DELAY, scanned it
1194 -- out and checked that the current token is UNTIL
1196 -- Error recovery: cannot raise Error_Resync
1198 function P_Delay_Until_Statement return Node_Id is
1199 Delay_Node : Node_Id;
1201 begin
1202 Delay_Node := New_Node (N_Delay_Until_Statement, Prev_Token_Ptr);
1203 Scan; -- past UNTIL
1204 Set_Expression (Delay_Node, P_Expression_No_Right_Paren);
1205 TF_Semicolon;
1206 return Delay_Node;
1207 end P_Delay_Until_Statement;
1209 -----------------------------------
1210 -- 9.6 Delay Relative Statement --
1211 -----------------------------------
1213 -- DELAY_RELATIVE_STATEMENT ::= delay delay_EXPRESSION;
1215 -- The caller has checked that the initial token is DELAY, scanned it
1216 -- out and determined that the current token is not UNTIL
1218 -- Error recovery: cannot raise Error_Resync
1220 function P_Delay_Relative_Statement return Node_Id is
1221 Delay_Node : Node_Id;
1223 begin
1224 Delay_Node := New_Node (N_Delay_Relative_Statement, Prev_Token_Ptr);
1225 Set_Expression (Delay_Node, P_Expression_No_Right_Paren);
1226 Check_Simple_Expression_In_Ada_83 (Expression (Delay_Node));
1227 TF_Semicolon;
1228 return Delay_Node;
1229 end P_Delay_Relative_Statement;
1231 ---------------------------
1232 -- 9.7 Select Statement --
1233 ---------------------------
1235 -- SELECT_STATEMENT ::=
1236 -- SELECTIVE_ACCEPT
1237 -- | TIMED_ENTRY_CALL
1238 -- | CONDITIONAL_ENTRY_CALL
1239 -- | ASYNCHRONOUS_SELECT
1241 -- SELECTIVE_ACCEPT ::=
1242 -- select
1243 -- [GUARD]
1244 -- SELECT_ALTERNATIVE
1245 -- {or
1246 -- [GUARD]
1247 -- SELECT_ALTERNATIVE
1248 -- [else
1249 -- SEQUENCE_OF_STATEMENTS]
1250 -- end select;
1252 -- GUARD ::= when CONDITION =>
1254 -- Note: the guard preceding a select alternative is included as part
1255 -- of the node generated for a selective accept alternative.
1257 -- SELECT_ALTERNATIVE ::=
1258 -- ACCEPT_ALTERNATIVE
1259 -- | DELAY_ALTERNATIVE
1260 -- | TERMINATE_ALTERNATIVE
1262 -- TIMED_ENTRY_CALL ::=
1263 -- select
1264 -- ENTRY_CALL_ALTERNATIVE
1265 -- or
1266 -- DELAY_ALTERNATIVE
1267 -- end select;
1269 -- CONDITIONAL_ENTRY_CALL ::=
1270 -- select
1271 -- ENTRY_CALL_ALTERNATIVE
1272 -- else
1273 -- SEQUENCE_OF_STATEMENTS
1274 -- end select;
1276 -- ENTRY_CALL_ALTERNATIVE ::=
1277 -- ENTRY_CALL_STATEMENT [SEQUENCE_OF_STATEMENTS]
1279 -- ASYNCHRONOUS_SELECT ::=
1280 -- select
1281 -- TRIGGERING_ALTERNATIVE
1282 -- then abort
1283 -- ABORTABLE_PART
1284 -- end select;
1286 -- TRIGGERING_ALTERNATIVE ::=
1287 -- TRIGGERING_STATEMENT [SEQUENCE_OF_STATEMENTS]
1289 -- TRIGGERING_STATEMENT ::= ENTRY_CALL_STATEMENT | DELAY_STATEMENT
1291 -- The caller has checked that the initial token is SELECT
1293 -- Error recovery: can raise Error_Resync
1295 function P_Select_Statement return Node_Id is
1296 Select_Node : Node_Id;
1297 Select_Sloc : Source_Ptr;
1298 Stmnt_Sloc : Source_Ptr;
1299 Ecall_Node : Node_Id;
1300 Alternative : Node_Id;
1301 Select_Pragmas : List_Id;
1302 Alt_Pragmas : List_Id;
1303 Statement_List : List_Id;
1304 Alt_List : List_Id;
1305 Cond_Expr : Node_Id;
1306 Delay_Stmnt : Node_Id;
1308 begin
1309 Push_Scope_Stack;
1310 Scope.Table (Scope.Last).Etyp := E_Select;
1311 Scope.Table (Scope.Last).Ecol := Start_Column;
1312 Scope.Table (Scope.Last).Sloc := Token_Ptr;
1313 Scope.Table (Scope.Last).Labl := Error;
1315 Select_Sloc := Token_Ptr;
1316 Scan; -- past SELECT
1317 Stmnt_Sloc := Token_Ptr;
1318 Select_Pragmas := P_Pragmas_Opt;
1320 -- If first token after select is designator, then we have an entry
1321 -- call, which must be the start of a conditional entry call, timed
1322 -- entry call or asynchronous select
1324 if Token in Token_Class_Desig then
1326 -- Scan entry call statement
1328 begin
1329 Ecall_Node := P_Name;
1331 -- ?? The following two clauses exactly parallel code in ch5
1332 -- and should be commoned sometime
1334 if Nkind (Ecall_Node) = N_Indexed_Component then
1335 declare
1336 Prefix_Node : constant Node_Id := Prefix (Ecall_Node);
1337 Exprs_Node : constant List_Id := Expressions (Ecall_Node);
1339 begin
1340 Change_Node (Ecall_Node, N_Procedure_Call_Statement);
1341 Set_Name (Ecall_Node, Prefix_Node);
1342 Set_Parameter_Associations (Ecall_Node, Exprs_Node);
1343 end;
1345 elsif Nkind (Ecall_Node) = N_Function_Call then
1346 declare
1347 Fname_Node : constant Node_Id := Name (Ecall_Node);
1348 Params_List : constant List_Id :=
1349 Parameter_Associations (Ecall_Node);
1351 begin
1352 Change_Node (Ecall_Node, N_Procedure_Call_Statement);
1353 Set_Name (Ecall_Node, Fname_Node);
1354 Set_Parameter_Associations (Ecall_Node, Params_List);
1355 end;
1357 elsif Nkind (Ecall_Node) = N_Identifier
1358 or else Nkind (Ecall_Node) = N_Selected_Component
1359 then
1360 -- Case of a call to a parameterless entry
1362 declare
1363 C_Node : constant Node_Id :=
1364 New_Node (N_Procedure_Call_Statement, Stmnt_Sloc);
1365 begin
1366 Set_Name (C_Node, Ecall_Node);
1367 Set_Parameter_Associations (C_Node, No_List);
1368 Ecall_Node := C_Node;
1369 end;
1370 end if;
1372 TF_Semicolon;
1374 exception
1375 when Error_Resync =>
1376 Resync_Past_Semicolon;
1377 return Error;
1378 end;
1380 Statement_List := P_Sequence_Of_Statements (SS_Eltm_Ortm_Tatm);
1382 -- OR follows, we have a timed entry call
1384 if Token = Tok_Or then
1385 Scan; -- past OR
1386 Alt_Pragmas := P_Pragmas_Opt;
1388 Select_Node := New_Node (N_Timed_Entry_Call, Select_Sloc);
1389 Set_Entry_Call_Alternative (Select_Node,
1390 Make_Entry_Call_Alternative (Stmnt_Sloc,
1391 Entry_Call_Statement => Ecall_Node,
1392 Pragmas_Before => Select_Pragmas,
1393 Statements => Statement_List));
1395 -- Only possibility is delay alternative. If we have anything
1396 -- else, give message, and treat as conditional entry call.
1398 if Token /= Tok_Delay then
1399 Error_Msg_SC
1400 ("only allowed alternative in timed entry call is delay!");
1401 Discard_Junk_List (P_Sequence_Of_Statements (SS_Sreq));
1402 Set_Delay_Alternative (Select_Node, Error);
1404 else
1405 Set_Delay_Alternative (Select_Node, P_Delay_Alternative);
1406 Set_Pragmas_Before
1407 (Delay_Alternative (Select_Node), Alt_Pragmas);
1408 end if;
1410 -- ELSE follows, we have a conditional entry call
1412 elsif Token = Tok_Else then
1413 Scan; -- past ELSE
1414 Select_Node := New_Node (N_Conditional_Entry_Call, Select_Sloc);
1416 Set_Entry_Call_Alternative (Select_Node,
1417 Make_Entry_Call_Alternative (Stmnt_Sloc,
1418 Entry_Call_Statement => Ecall_Node,
1419 Pragmas_Before => Select_Pragmas,
1420 Statements => Statement_List));
1422 Set_Else_Statements
1423 (Select_Node, P_Sequence_Of_Statements (SS_Sreq));
1425 -- Only remaining case is THEN ABORT (asynchronous select)
1427 elsif Token = Tok_Abort then
1428 Select_Node :=
1429 Make_Asynchronous_Select (Select_Sloc,
1430 Triggering_Alternative =>
1431 Make_Triggering_Alternative (Stmnt_Sloc,
1432 Triggering_Statement => Ecall_Node,
1433 Pragmas_Before => Select_Pragmas,
1434 Statements => Statement_List),
1435 Abortable_Part => P_Abortable_Part);
1437 -- Else error
1439 else
1440 if Ada_Version = Ada_83 then
1441 Error_Msg_BC ("OR or ELSE expected");
1442 else
1443 Error_Msg_BC ("OR or ELSE or THEN ABORT expected");
1444 end if;
1446 Select_Node := Error;
1447 end if;
1449 End_Statements;
1451 -- Here we have a selective accept or an an asynchronous select (first
1452 -- token after SELECT is other than a designator token).
1454 else
1455 -- If we have delay with no guard, could be asynchronous select
1457 if Token = Tok_Delay then
1458 Delay_Stmnt := P_Delay_Statement;
1459 Statement_List := P_Sequence_Of_Statements (SS_Eltm_Ortm_Tatm);
1461 -- Asynchronous select
1463 if Token = Tok_Abort then
1464 Select_Node :=
1465 Make_Asynchronous_Select (Select_Sloc,
1466 Triggering_Alternative =>
1467 Make_Triggering_Alternative (Stmnt_Sloc,
1468 Triggering_Statement => Delay_Stmnt,
1469 Pragmas_Before => Select_Pragmas,
1470 Statements => Statement_List),
1471 Abortable_Part => P_Abortable_Part);
1473 End_Statements;
1474 return Select_Node;
1476 -- Delay which was not an asynchronous select. Must be a selective
1477 -- accept, and since at least one accept statement is required,
1478 -- we must have at least one OR phrase present.
1480 else
1481 Alt_List := New_List (
1482 Make_Delay_Alternative (Stmnt_Sloc,
1483 Delay_Statement => Delay_Stmnt,
1484 Pragmas_Before => Select_Pragmas,
1485 Statements => Statement_List));
1486 T_Or;
1487 Alt_Pragmas := P_Pragmas_Opt;
1488 end if;
1490 -- If not a delay statement, then must be another possibility for
1491 -- a selective accept alternative, or perhaps a guard is present
1493 else
1494 Alt_List := New_List;
1495 Alt_Pragmas := Select_Pragmas;
1496 end if;
1498 Select_Node := New_Node (N_Selective_Accept, Select_Sloc);
1499 Set_Select_Alternatives (Select_Node, Alt_List);
1501 -- Scan out selective accept alternatives. On entry to this loop,
1502 -- we are just past a SELECT or OR token, and any pragmas that
1503 -- immediately follow the SELECT or OR are in Alt_Pragmas.
1505 loop
1506 if Token = Tok_When then
1508 if Present (Alt_Pragmas) then
1509 Error_Msg_SC ("pragmas may not precede guard");
1510 end if;
1512 Scan; -- past WHEN
1513 Cond_Expr := P_Expression_No_Right_Paren;
1514 T_Arrow;
1515 Alt_Pragmas := P_Pragmas_Opt;
1517 else
1518 Cond_Expr := Empty;
1519 end if;
1521 if Token = Tok_Accept then
1522 Alternative := P_Accept_Alternative;
1524 -- Check for junk attempt at asynchronous select using
1525 -- an Accept alternative as the triggering statement
1527 if Token = Tok_Abort
1528 and then Is_Empty_List (Alt_List)
1529 and then No (Cond_Expr)
1530 then
1531 Error_Msg
1532 ("triggering statement must be entry call or delay",
1533 Sloc (Alternative));
1534 Scan; -- past junk ABORT
1535 Discard_Junk_List (P_Sequence_Of_Statements (SS_Sreq));
1536 End_Statements;
1537 return Error;
1538 end if;
1540 elsif Token = Tok_Delay then
1541 Alternative := P_Delay_Alternative;
1543 elsif Token = Tok_Terminate then
1544 Alternative := P_Terminate_Alternative;
1546 else
1547 Error_Msg_SC
1548 ("Select alternative (ACCEPT, ABORT, DELAY) expected");
1549 Alternative := Error;
1551 if Token = Tok_Semicolon then
1552 Scan; -- past junk semicolon
1553 end if;
1554 end if;
1556 -- THEN ABORT at this stage is just junk
1558 if Token = Tok_Abort then
1559 Error_Msg_SP ("misplaced `THEN ABORT`");
1560 Scan; -- past junk ABORT
1561 Discard_Junk_List (P_Sequence_Of_Statements (SS_Sreq));
1562 End_Statements;
1563 return Error;
1565 else
1566 if Alternative /= Error then
1567 Set_Condition (Alternative, Cond_Expr);
1568 Set_Pragmas_Before (Alternative, Alt_Pragmas);
1569 Append (Alternative, Alt_List);
1570 end if;
1572 exit when Token /= Tok_Or;
1573 end if;
1575 T_Or;
1576 Alt_Pragmas := P_Pragmas_Opt;
1577 end loop;
1579 if Token = Tok_Else then
1580 Scan; -- past ELSE
1581 Set_Else_Statements
1582 (Select_Node, P_Sequence_Of_Statements (SS_Ortm_Sreq));
1584 if Token = Tok_Or then
1585 Error_Msg_SC ("select alternative cannot follow else part!");
1586 end if;
1587 end if;
1589 End_Statements;
1590 end if;
1592 return Select_Node;
1593 end P_Select_Statement;
1595 -----------------------------
1596 -- 9.7.1 Selective Accept --
1597 -----------------------------
1599 -- Parsed by P_Select_Statement (9.7)
1601 ------------------
1602 -- 9.7.1 Guard --
1603 ------------------
1605 -- Parsed by P_Select_Statement (9.7)
1607 -------------------------------
1608 -- 9.7.1 Select Alternative --
1609 -------------------------------
1611 -- SELECT_ALTERNATIVE ::=
1612 -- ACCEPT_ALTERNATIVE
1613 -- | DELAY_ALTERNATIVE
1614 -- | TERMINATE_ALTERNATIVE
1616 -- Note: the guard preceding a select alternative is included as part
1617 -- of the node generated for a selective accept alternative.
1619 -- Error recovery: cannot raise Error_Resync
1621 -------------------------------
1622 -- 9.7.1 Accept Alternative --
1623 -------------------------------
1625 -- ACCEPT_ALTERNATIVE ::=
1626 -- ACCEPT_STATEMENT [SEQUENCE_OF_STATEMENTS]
1628 -- Error_Recovery: Cannot raise Error_Resync
1630 -- Note: the caller is responsible for setting the Pragmas_Before
1631 -- field of the returned N_Terminate_Alternative node.
1633 function P_Accept_Alternative return Node_Id is
1634 Accept_Alt_Node : Node_Id;
1636 begin
1637 Accept_Alt_Node := New_Node (N_Accept_Alternative, Token_Ptr);
1638 Set_Accept_Statement (Accept_Alt_Node, P_Accept_Statement);
1640 -- Note: the reason that we accept THEN ABORT as a terminator for
1641 -- the sequence of statements is for error recovery which allows
1642 -- for misuse of an accept statement as a triggering statememt.
1644 Set_Statements
1645 (Accept_Alt_Node, P_Sequence_Of_Statements (SS_Eltm_Ortm_Tatm));
1646 return Accept_Alt_Node;
1647 end P_Accept_Alternative;
1649 ------------------------------
1650 -- 9.7.1 Delay Alternative --
1651 ------------------------------
1653 -- DELAY_ALTERNATIVE ::=
1654 -- DELAY_STATEMENT [SEQUENCE_OF_STATEMENTS]
1656 -- Error_Recovery: Cannot raise Error_Resync
1658 -- Note: the caller is responsible for setting the Pragmas_Before
1659 -- field of the returned N_Terminate_Alternative node.
1661 function P_Delay_Alternative return Node_Id is
1662 Delay_Alt_Node : Node_Id;
1664 begin
1665 Delay_Alt_Node := New_Node (N_Delay_Alternative, Token_Ptr);
1666 Set_Delay_Statement (Delay_Alt_Node, P_Delay_Statement);
1668 -- Note: the reason that we accept THEN ABORT as a terminator for
1669 -- the sequence of statements is for error recovery which allows
1670 -- for misuse of an accept statement as a triggering statememt.
1672 Set_Statements
1673 (Delay_Alt_Node, P_Sequence_Of_Statements (SS_Eltm_Ortm_Tatm));
1674 return Delay_Alt_Node;
1675 end P_Delay_Alternative;
1677 ----------------------------------
1678 -- 9.7.1 Terminate Alternative --
1679 ----------------------------------
1681 -- TERMINATE_ALTERNATIVE ::= terminate;
1683 -- Error_Recovery: Cannot raise Error_Resync
1685 -- Note: the caller is responsible for setting the Pragmas_Before
1686 -- field of the returned N_Terminate_Alternative node.
1688 function P_Terminate_Alternative return Node_Id is
1689 Terminate_Alt_Node : Node_Id;
1691 begin
1692 Terminate_Alt_Node := New_Node (N_Terminate_Alternative, Token_Ptr);
1693 Scan; -- past TERMINATE
1694 TF_Semicolon;
1696 -- For all other select alternatives, the sequence of statements
1697 -- after the alternative statement will swallow up any pragmas
1698 -- coming in this position. But the terminate alternative has no
1699 -- sequence of statements, so the pragmas here must be treated
1700 -- specially.
1702 Set_Pragmas_After (Terminate_Alt_Node, P_Pragmas_Opt);
1703 return Terminate_Alt_Node;
1704 end P_Terminate_Alternative;
1706 -----------------------------
1707 -- 9.7.2 Timed Entry Call --
1708 -----------------------------
1710 -- Parsed by P_Select_Statement (9.7)
1712 -----------------------------------
1713 -- 9.7.2 Entry Call Alternative --
1714 -----------------------------------
1716 -- Parsed by P_Select_Statement (9.7)
1718 -----------------------------------
1719 -- 9.7.3 Conditional Entry Call --
1720 -----------------------------------
1722 -- Parsed by P_Select_Statement (9.7)
1724 --------------------------------
1725 -- 9.7.4 Asynchronous Select --
1726 --------------------------------
1728 -- Parsed by P_Select_Statement (9.7)
1730 -----------------------------------
1731 -- 9.7.4 Triggering Alternative --
1732 -----------------------------------
1734 -- Parsed by P_Select_Statement (9.7)
1736 ---------------------------------
1737 -- 9.7.4 Triggering Statement --
1738 ---------------------------------
1740 -- Parsed by P_Select_Statement (9.7)
1742 ---------------------------
1743 -- 9.7.4 Abortable Part --
1744 ---------------------------
1746 -- ABORTABLE_PART ::= SEQUENCE_OF_STATEMENTS
1748 -- The caller has verified that THEN ABORT is present, and Token is
1749 -- pointing to the ABORT on entry (or if not, then we have an error)
1751 -- Error recovery: cannot raise Error_Resync
1753 function P_Abortable_Part return Node_Id is
1754 Abortable_Part_Node : Node_Id;
1756 begin
1757 Abortable_Part_Node := New_Node (N_Abortable_Part, Token_Ptr);
1758 T_Abort; -- scan past ABORT
1760 if Ada_Version = Ada_83 then
1761 Error_Msg_SP ("(Ada 83) asynchronous select not allowed!");
1762 end if;
1764 Set_Statements (Abortable_Part_Node, P_Sequence_Of_Statements (SS_Sreq));
1765 return Abortable_Part_Node;
1766 end P_Abortable_Part;
1768 --------------------------
1769 -- 9.8 Abort Statement --
1770 --------------------------
1772 -- ABORT_STATEMENT ::= abort task_NAME {, task_NAME};
1774 -- The caller has checked that the initial token is ABORT
1776 -- Error recovery: cannot raise Error_Resync
1778 function P_Abort_Statement return Node_Id is
1779 Abort_Node : Node_Id;
1781 begin
1782 Abort_Node := New_Node (N_Abort_Statement, Token_Ptr);
1783 Scan; -- past ABORT
1784 Set_Names (Abort_Node, New_List);
1786 loop
1787 Append (P_Name, Names (Abort_Node));
1788 exit when Token /= Tok_Comma;
1789 Scan; -- past comma
1790 end loop;
1792 TF_Semicolon;
1793 return Abort_Node;
1794 end P_Abort_Statement;
1796 end Ch9;